Fuel pump with crimped cover seal



Aug. 15, 1967 D. TOSCHKOFF 3,335,641

FUEL PUMP WITH CRIMPED COVER SEAL Filed Jan. 19. 1966 ATTORNEY UnitedStates Patent 3,335,641 FUEL PUMP WITH CRIMPED COVER SEAL DiinitarToschkoff, Flint, Mich., assignor to General Motors Corporation,Detroit, Mich., a corporation of Delaware Filed Jan. 19, 1966, Ser. No.521,628 Claims. (Cl. 92-100) ABSTRACT OF THE DISCLOSURE A fuel pumphaving a casing of three parts, two of which are of sheet metal and theother having a flange being of thicker or more rigid material, theflange and peripheries of the two parts being joined together bycrimping to form a tight seal without the use of a yielding sealingmaterial other than that of a pumping diaphragm margin constrained bythe casing.

This invention relates to pumps and more particularly to diaphragm typepumps such as used in providing fuel to automobile engines.

The US. patent application SN. 489,104, filed Sept. 22, 1965, in thename of Dimitar Toschkolf discloses a fuel pump generally similar inover-all concept to the pump described herein. In that application,joining of two outer casing parts and an intermediate part bearing inletand outlet valves is done to secure a fluid-tight casing. A yieldable orrelatively soft pumping diaphragm margin is retained as a part of thejoint and a satisfactory seal of the casing is achieved. After extendedor severe service, however, leaks have sometimes occurred in the jointprovided and it is to this problem that the present invention isdirected. An obvious solution has been to apply a sealing composition atthe interface of one exterior part with an intermediate or inner part ofthe casing and to rely upon the sealing elfect of the diaphragm materialbetween the intermediate part and the other exterior or main part of thecasing. The application of the sealing composition is an added expenseand, during volume production, the added step or steps, though feasible,are objectionable for other obvious reasons.

Important features of the present invention Will now be described indetail and then pointed out more particularly in the appended claims.

In the drawings:

FIGURE 1 is an elevation view of a fuel pump embodying the presentinvention, parts being broken away better to illustrate pertinentdetails;

FIGURE 2 is an enlarged sectional view of a peripheral seal or jointshown in FIGURE 1; and

FIGURE 3 is a sectional view looking in the direction of the arrows 33in FIGURE 1.

In FIGURE 1 a fuel pump is disclosed having a casing of three main parts10, 12 and 14. The part is in the form of a casting with a rigid annularflange 16 and this part 10 cooperates with a flexible pumping diaphragm18 to define a pumping spring chamber 20.

As is conventional in automobile pumps, the part 10 is utilized tosupport the pump on an engine and the diaphragm 18 is adapted toreciprocate by virtue of the action of the engine through a plunger 22,a rocker arm 24 and a diaphragm plunger 26 for moving the diaphragm 18in one direction and by a spring 28 for moving the diaphragm in theother direction. The casing part 12, as well as the part 14, is made ofsheet metal and in the present instance the part 12 supports inlet andoutlet valves (not shown) which form no part of the present invention.It is to be noted, however, that the rigid flange 16 of the casing part10 has a radially curved wall recess 30 and a radial, flat or annularwall 32. The inner sheet metal part 12 of the casing bears at least fourradially extending projections 34 snugly received within a cylindricalwall of the casing part 14. The part 12 also has a sharp peripheral edgeat 36 which is adapted to engage a radial flange surface 38 of the part14. It will be noted that the interrelationship of the three casingparts is such that two annular clamping zones are effected with respectto the pumping diaphragm 18. Sections of these two clamping zonesdesignate them in FIGURE 2 as zone A and zone B.

The casing part 14 is made in the form of a cup and it not only snuglyreceives the casing part 12 at the projections 34 and evenly engages thesharp downturned edge 36 of the part 12, but it also bears a marginalportion 40 which is crimped around the rigid flange 16 tightly to holdthe three casing parts together in fluid tight relation.

It will be noted that the spring chamber 20 is sealed from theatmosphere at both zones A and B. The chamber 42 existing between thediaphragm 18 and the casing part 12 is sealed from the atmosphere atzones A and B and also from the chamber 44 (latter is beneath part 12)at zone A. The chamber 44 is sealed from the atmosphere at zone B andconstitutes an outlet chamber.

I claim:

1. A fuel pump comprising a fluid tight casing of three parts, one ofsaid parts having a rigid peripheral flange, the second andthird of saidparts being of sheet metal, an annular recess with a radially curvedwall formed in said rigid flange, a pumping diaphragm of flexiblerelatively soft material and having a diameter greater than that of saidsecond part, said diaphragm having two adjacent annular clampedportions, one of said clamped portions being retained in said recess bysaid second part to form one annular sealing zone, the other of saidclamped portions being between said flange and said third part to form asecond annular sealing zone, and said annular sealing zones beingcoaxial with said pumping diaphragm.

2. A fuel pump as set forth in claim 1, and said third part having anintegral flange crimped around said rigid flange to hold said threeparts together.

3. A fuel pump as set forth in claim 1, said second sheet metal parthaving a sharp annular peripheral edge engaging said third part at anangle.

4. A fuel pump as set forth in claim 1, said second sheet metal parthaving a series of spaced radially extending projections maintainingsaid second and third parts coaxially.

5. A fuel pump comprising a fluid tight casing of three parts, one ofsaid parts having a rigid and thick flange, the second and third of saidparts being of relatively thin sheet metal, an annular recess in saidrigid flange, said recess having a curved wall, a pumping diaphragminterposed beween said flange and said second part to form a seal withsaid wall of said recess at one side of said diaphragm and said thirdpart retaining said diaphrgam against said flange to form a second sealat the other side of said diaphragm, and said second part having anannular peripheral edge engaging said third part at an angle and aseries of spaced radially extending projections, said edge andprojections being arranged to maintain the relative positioning of saidsecond and third parts.

(References on following page) 3 4 References Cited 3,115,162 12/1965Posh 138-30 NIT STATES PA 3,278,032 10/1966 Smith 103-150 2/1929 y 92 983,304,880 2/1967 Gold et a1 103--150 5/1958 Coffey 103-450 9/1959Johnson 5 DONLEY I. STOCKING, Primary Exammer. 11/1960 Shoosmith 103-150WILLIAM L. FREEH, Examiner.

1. A FUEL PUMP COMPRISING A FLUID TIGHT CASING OF THREE PARTS, ONE OFSAID PARTS HAVING A RIGID PERIPHERAL FLANGE, THE SECOND AND THIRD OFSAID PARTS BEING OF SHEET METAL, AN ANNULAR RECESS WITH A RADIALLYCURVED WALL FORMED IN SAID RIGID FLANGE, A PUMPING DIAPHRAGM OF FLEXIBLERELATIVELY SOFT MATERIAL AND HAVING A DIAMETER GREATER THAN THAT OF SAIDSECOND PART, SAID DIAPHRAGM HAVING TWO ADJACENT ANNULAR CLAMPEDPORTIONS, ONE OF SAID CLAMPED PORTIONS BEING RETAINED IN SAID RECESS BYSAID SECOND PART TO FORM ONE ANNULAR SEALING ZONE, THE OTHER OF SAIDCLAMPED PORTIONS BEING BETWEEN SAID FLANGE AND